Exclusive C7

Commentary

In search of true stereophonic, we have applied our technology without fail to create L, which can be called the origin of stereophonic.
This is a high-end stereo preamplifier with the aim of "0 stereo transmission error" which reproduces sound from R as homogeneous sound.

It uses a completely independent monoconstruction structure from the power cord to the input / output terminals on the rear panel.
In addition, we thoroughly analyze the magnetic field, temperature, vibration, etc. inside the set that affect the reproduction of the same left and right by making full use of the latest measuring equipment, and use newly developed parts and layout of all parts of the left and right independently symmetrical type to ensure the same transmission.
In addition, various considerations are taken to achieve 0 stereo transmission error, such as simplification of signal path and adoption of in-set remote control system.

The magnetic field generated by power transformers and smoothing capacitors affects the transmission circuit, generating inductive noise and degrading sound quality. We have developed a power transformer with a low magnetic flux density, a capacitor that cancels the magnetic field, and other anti-magnetic measures for major components and uniform magnetic distribution within the set.

Taking into account the effects of external and internal vibrations of the amplifier, we have developed and adopted a newly developed low-flux transformer and a capacitor (complimentary service capacitor pair) in which the positive side and the negative side cancel each other's magnetism.
In addition, anti-vibration and anti-vibration measures such as floating printed circuit boards and an aluminum die-cast chassis with no resonance are implemented.
In addition, in order to cope with deformation due to heat of the chassis, we have adopted a chassis with calculated stress and designed the layout of each part taking into account the effects of thermal deformation, etc., to clarify and respond to the effects of mechanical elements on sound quality.

Taking into consideration that the characteristics of conductors whose resistance changes with temperature affect sound quality, we control heat radiation and provide appropriate layout of heat source parts to create a temperature environment similar to a constant temperature chamber in order to equalize sound on the left and right sides.

In order to ensure the independence of the perfect monoconstruction in which the left and right are completely independent, the volume and function switch also adopt the remote control in the set, and the left and right are clearly separated.

The circuit configuration is 1-channel 2-amplifier 2-buffer amplifier configuration.
In order to drive the volume and Rec output with low impedance from the input with high impedance, a buffer amplifier is installed between the input selector and the volume, and between the volume and the phase switch. In addition, two flat amplifiers use an amplifier circuit made of aluminum hybrid IC.

The power supply section is independent of three transformers for left, right and control. In order to eliminate the influence on sound quality, a power transformer which operates at a low magnetic flux density is adopted from Shinkai. Noise generation is suppressed by setting it to operate at a point with good linearity.
In addition, we have developed a new complimentary service capacitor pair that focuses on the magnetic field generated on the plus side and the minus side of the smoothing capacitor and cancels each other, thereby reducing the effect of the magnetic field on sound quality.

In order to completely eliminate noise and ensure the purity of the signal from the source, the input circuit uses a separate ground circuit that turns on/off not only the hot side but also the ground side at the same time. This eliminates noise from other equipment coming in from the ground line.

Aluminum, which has excellent thermal conductivity and shielding characteristics, is used for the substrate of the hybrid IC used in the amplification part of the flat amplifier, thereby thoroughly suppressing the influence of heat and magnetism, which cause sound quality degradation, on sound quality.

The printed circuit board, which is easily affected by vibration, is floated from the holder with dump material of special vibration insulating rubber, and the effect of vibration on sound quality is eliminated.

In order to obtain independence of each channel and symmetry of left and right, an in-set remote control system is adopted for switching between volume and function to ensure left and right independence.
When the front panel control is operated manually, the volume and function selector switches located at the rear of the set are driven by the motor and set to the desired position.
If no operation is performed, the motor-drive generator is turned off and the effect on sound quality is cut off.

In order to reproduce excellent sound quality, each part is carefully examined, and 99.99% pure oxygen-free copper shielded wire is used for signal path wiring.

In order to supply energy directly to each of the three transformers, a 6-core oxygen-free copper high-quality extra-thick power cord is used.
In addition to double insulation, carbon is used as the coloring pigment of the insulation material to cope with the influence of pigments on sound quality.

Model Rating

Type	Stereo preamplifier
Input Sensitivity / Impedance	Phono MM : 2.5mV/50k Ω CD, Tuner, Line1, 2, 3, 4, 5, Tape play1, Tape2 : 150mV/50k Ω Balance in 1, 2 : 150mV/600 Ω
Output Level / Impedance	Tape rec1, 2 : 150mV/1k Ω Output1 : 1V/0.1 Ω Output2 (Balance) : 1V/200 Ω
Maximum output level (Distortion rate 0.01%, 20 Hz to 20 kHz)	Tape rec1, 2 : 12 V (at phono) or more Line4, 5 out : 12 V (at phono) or more Output1 : 5 V or more / 600 Ω Output2 (Balance) : 3 V or more / 600 Ω, 5 V or more / 10k Ω
Phono maximum allowable input	Phono MM : 200 mV or more (1 kHz, distortion rate 0.01%)
Signal-to-noise ratio	Phono MM:87dB Aux:105dB
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	70W (Electrical Appliance and Material Control Law)
External dimensions	Width 460x Height 158x Depth 446 mm
Weight	27.5kg